Oxamyl chloride substituted carbamates



United States Patent 3,539,618 OXAMYL CHLORIDE SUBSTITUTED CARBAMATESPaul J. Stoifel, St. Louis, Mo., assignor to Monsanto Company, St.Louis, Mo., a corporation of Delaware No Drawing. Continuation-impart ofapplication Ser. No. 310,847, Sept. 23, 1963. This application Apr. 15,1966,

Ser. No. 542,749

Int. Cl. C07c 103/32 US. Cl. 260-471 7 Claims ABSTRACT OF THE DISCLOSURECarbamides of the formula wherein R is selected from the groupconsisting of hydrocarbyl and substituted hydrocarbyl having up to foursubstituents, wherein the hydrocarbyl is selected from the groupconsisting of primary alkyl of not more than 12 carbon atoms, benzyl andphenyl, and wherein the substituents on the hydrocarbyl are selectedfrom the group consisting of nitro, chlorine, bromine, alkoxy of notmore than 4 carbon atoms, alkyl of not more than 4 carbon atoms andphenyl; and R is selected from the group consisting of hydrocarbyl andsubstituted hydro carbyl having up to four substituents, wherein thehydrocarbyl is selected from the group consisting of alkyl of not morethan 12 carbon atoms, alkenyl of not more than 12 carbon atoms,cycloaliphatic having at least 4 and not more than 8 carbon atoms,benzyl and phenyl, and wherein the substituents on the hydrocarbyl areselected from the group consisting of chlorine, bromine, nitro, alkyl ofnot more than 4 carbon atoms, alkoxy of not more than 4 carbon atoms andphenyl are useful in the control of plant systems and pathogenicmicroorganisms.

This application is a continuation-in-part of application Ser. No.310,847, filed Sept. 23, 1963, now abandoned.

This invention relates to novel carbamides and to processes for theirpreparation. The carbamides of this invention have biological toxicantproperties and can be used r to control the growth of plant systems andto control pathogenic microorganisms.

The carbamides of this invention are prepared by a process whichcomprises reacting an N-substituted car bamic acid ester with oxalylchloride in accordance with r the following representative synthesis:

consisting of nitro, chlorine, bromine, alkoxy of not more than 4 carbonatoms, alkyl of not more than 4 carbon atoms and phenyl; and R isselected from the group consisting of hydrocarbyl and substitutedhydrocarbyl having up to four substituents, wherein the hydrocarbyl isselected from the group consisting of alkyl of not more than 12 carbonatoms, alkenyl of not more than 12 carbon atoms, cycloaliphatic havingat least 4 and not more than 8 carbon atoms, benzyl and phenyl, andwherein the substituents on the hydrocarbyl are selected from the groupconsisting of chlorine, bromine, nitro, alkyl of not more than 4 carbonatoms, alkoxy of not more than 4 carbon atoms and phenyl.

The process of this invention by which the carbamides are preparedinvolves reacting oxalyl chloride with a substantially equimolar amountof an N-substituted carbamic acid ester of the defined configuration.The N-substituents can vary widely but the esterifying group must be oneof the narrower scope to eliect the formation of the new compounds. Thereaction is conducted in an inert aromatic solvent medium, for examplebenzene, xylene, toluene, chloroxylene, chlorotoluene,1,4-dichlorobenzene and other aromatic and halogen substituted aromatichydrocarbons. The reaction mixture should be heated but temperatures aslow as about 30 C. will effect a useful result. Higher temperatures, forexample the reflux temperature of the chosen solvent medium, producepreferred rates of reaction. Temperatures as high as about C. will beuseful; however, decomposition of the product takes place if thistemperature is exceeded.

When the reaction has been completed or has proceeded to a desiredextent, the product can be separated from the solvent medium by theaddition of a suitable non-solvent which is miscible with the solventmedium, for example n-hexane or any other aliphatic petroleum fraction.This reduces the solubility of the product in the solvent medium andcauses precipitation of the product. The reduction in temperature alsoaids in the separation of the desired product. The solid product can beseparated by filtration and purified, if desired, by recrystallizationfrom a suitable solvent, for example acetone.

Further details of the procedure and the novel compounds so prepared areset forth in the following examples.

EXAMPLE 1 A solution of 22 grns. of methyl 3,4-dichlorocarbanilate and12.7 gms. of oxalyl chloride in 50 ml. benzene was heated at refluxtemperature for six hours. The product N- 3,4-dichlorophenyl-N-carbomethoxyoxamyl chloride was separated from the benzene by theaddition of 200 ml. of hexane to the cooled solution. Uponrecrystallization from toluene white platelike crystals (M.P. 100.4 to1012 C.) were formed.

EXAMPLE 2 The procedure of Example 1 was repeated except that ethyl3,4-dichlorocarbanilate was used in place of the methyl ester. Theresulting product (M.P. 102-l03 C.) was found to have the structure itil-O-CH2-CH:

3 EXAMPLE 3 The reaction product of oxalyl chloride and n-propyl3,4-dichlorocarbani1ate was found to have a melting point of 5657 C. andthe structure The phenyl ester of N-allylcarbarnic acid was heated withoxalyl chloride in a toluene solution. The resulting product was foundto have the structure:

Q oo CH2=CHCHz-N GGC1 II I! O 0 EXAMPLE 5 Benzyl N-ethylcarbamate washeated at reflux tempera ture with oxalyl chloride in a1,4-dichlor0benzene solution. After refluxing for three hours theproduct was identified as that of the structure:

HaQz-N arr- 0 6 EXAMPLE 6 Using the procedure of Example 1 oxalylchloride was reacted with phenyl N-3,4-dichlorocarbanilate in a xylenesolution. Heating at reflux temperature for four hours produced areaction mixture which upon cooling and dilution with n-hexane produceda product of the structure:

C-(fi-Cl o 0 EXAMPLE 7 The reaction at reflux temperature in achlorotoluene solution between oxalyl chloride and Z-ethylhexylcarbanilate produced a product of the structure:

EXAMPLE 8 Using the procedure of Example 1 except that n-butylN-cyclohexylcarbamate was used in place of the methyl3,4-dichlorocarbanilate. The product was identified asN-carbobutoxy-N-cyclohexane oxamoyl chloride,

EXAMPLE 9 In a toluene solution oxamyl chloride and N-benzyln-propylcarbamate were heated at 115 C. for 16 hours. The product wasidentified as N-benzyl-N-carbon-n-propoxy oxamyl chloride.

EXAMPLE A xylene solution containing equal mols of oxalyl chloride andN-ethylmethylcarbamate was heated at reflux for 10 hours. The productwas identified as having the structure:

ll II Useful compounds may also be prepared by reacting oxalyl chloridewith other esters of N-substituted carbamic acids by the proceduresabove described to obtain the following:

O G H2---- 0 H3 Although the invention has been described with respectto specific modifications, it is not intended that the details thereofshall be limitations on the scope of the invention except to the extentincorporated in the following claims.

What is claimed is:

1. Compound of the formula II 0-0 B wherein R is selected from the groupconsisting of hydrocarbyl and substituted hydrocarbyl having up to foursubstituents, wherein the hydrocarbyl is selected from the groupconsisting of primary alkyl of not more than 12 carbon atoms, benzyl andphenyl, and wherein the substituents on the hydrocarbyl are selectedfrom the group consisting of nitro, chlorine, bromine, alkoxy of notmore than 4 carbon atoms, alkyl of not more than 4 carbon atoms andphenyl; and R is selected from the group consisting of hydrocarbyl andsubstituted hydrocarbyl having up to four substituents, wherein thehydrocarbyl is selected from the group consisting of alkyl of not morethan 12 carbon atoms, alkenyl of not more than 12 carbon atoms,cycloaliphatic having at least 4 and not more than 8 carbon atoms,benzyl and phenyl, and wherein the substituents on the hydrocarbyl areselected from the group consisting of chlorine, bromine, nitro, alkyl ofnot more than 4 carbon atoms, alkoxy of not more than 4 carbon atoms andphenyl.

2. Compound of claim 1 wherein R is primary alkyl of not more than 12carbon atoms.

3. Compound of claim 1 which is N-3,4-dichlorophenyl- N-carbomethoxyoxamyl chloride.

4. Compound of claim 1 which is N-benzyl-N-carbo-npropoxy oxamylchloride.

5. Compound of claim 1 which is N-ethyl-N-carbobenzoxy oxamyl chloride.

6. Compound of claim 1 which is N-(n-propyl)-N- carbophenoxy oxamylchloride.

7. Compound of claim 1 which is N-ethyl-N-carboxymethoxy oxamylchloride.

6 References Cited Compt. Rend. by Najer et 211., vol. 242 (1956), pages2727-2729 relied on.

LORRAINE A. WEINBERGER, Primary Examiner L. A. THAXTON, AssistantExaminer US. Cl. X.R.

